Banca de DEFESA: MYRIAM GALVAO NEVES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MYRIAM GALVAO NEVES
DATE: 28/09/2020
TIME: 15:00
LOCAL: Na residência de cada membro por videoconferência
TITLE:

BIOCHEMICAL METABOLISM, PRODUCTION AND POST-HARVEST EVALUATION IN LETTUCE PLANTS SUBMITTED TO THE APPLICATION OF FOLIAR SILICON

KEY WORDS:

Lactuca sativa L., beneficial element, shelf time, horticulture, mineral nutrition.

PAGES: 55
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Fertilidade do Solo e Adubação
SUMMARY:

Lettuce is considered the most consumed leafy vegetable in Brazil, however, some obstacles need to be overcome in this productive chain, such as its short shelf life, due to its high water content in its composition, favoring its deterioration and poor quality. However, studies have shown positive results in the use of silicate fertilizer in several agricultural crops, because, when accumulated in the leaf cuticle, it promotes a reduction in water loss. In the same way, Si can also act on the metabolism of carbon and nitrogen. Therefore, the objective of the study was to determine the effects of silicon doses via leaf on growth, production, post-harvest conservation and biochemical metabolism in curly lettuce plants in a greenhouse in two application times. Four experiments were carried out, and in Experiment I, a 2x5 factorial scheme was followed, with the sources of calcium silicate and sodium metasilicate and five doses of silicon: 0, 2, 4, 6, 8 mg L^-1 Si, with six repetitions, lettuce plants being grown in pots filled with substrate. In experiment II, three lettuce plants were removed and taken to the refrigerator, weighing at intervals of five and 10 days for post-harvest evaluation. Experiment III was in randomized blocks, factorial 5x2, with four replications, totaling 10 treatments, (5 doses of Si: 0; 2; 4; 6 and 8 mg L^-1 and two application times: 20 and 27 DAT). The IV experiment was in subdivided plots, with 5 doses of Si (0; 2; 4; 6 and 8 mg L^-1), two times of foliar application (20 and 27 DAT), with four weighing intervals (5, 10, 15 and 20 days) and three replications, the lettuces were grown in Leonard pots, filled with sand, receiving nutrient solution. It is concluded that in experiment I and II in the tested concentrations there is a beneficial effect of silicon in the form of calcium silicate, with increments in the number of leaves, fresh and dry mass of the stem, fresh and dry mass of leaves, fresh and dry mass of shoots, fresh and dry mass of roots, reduced water loss during the post-harvest conservation period and the use of sodium metasilicate via foliar application in plants is not recommended of lettuce. In experiments III and IV, the foliar application of Si influenced the growth variables: height, length and fresh root mass, and the biochemical variables: protein, ammonium and nitrate content. The lowest water loss occurred at 20 DAT when compared to application at 27 DAT

BANKING MEMBERS:
Presidente - 1228204 - MARIO LOPES DA SILVA JUNIOR
Externo à Instituição - EDUARDO CEZAR MEDEIROS SALDANHA - YARA
Externo à Instituição - GERSON DIEGO PAMPLONA ALBUQUERQUE
Externo à Instituição - GLAUCO ANDRÉ DOS SANTOS NOGUEIRA - UFRA
Externa à Instituição - HELLEN SIGLIA DEMETRIO BARROS - SENAR